Meta

Even though the argument from reason may sound good, the argument is a good example of begging the question (I.E. circular reasoning). The premise (that physical sources cannot constitute a rational source) is the conclusion (That naturalism – which says physical sources can constitute a rational source – is wrong). The reason that this is hard to see initially is due to the way in which the argument is laid out.

I think this is flatly incorrect. Saying that physical causes cannot be rational is not the same as saying naturalism is false. I think it gives a good reason to reject naturalism, but it might turn out that we are not rational and naturalism is true.

The central point of the argument is that merely physical sources cannot constitute a rational source, and therefore Lewis (and others) come to the conclusion that naturalism is self-refuting. Yet this premise is left without a proper explanation, and I don’t see why merely physical sources cannot constitute a rational source – in fact, this is one of the things that naturalism argues – that rationality can arise out of a purely physical source. A person employing the Argument from Rationality simply posits as a premise that it cannot, and then claims that this makes naturalism self-refuting. Obviously, we could refute nearly any worldview in this manner. Similarly, we could claim that any abstraction – from love to opinions to ideas to art – cannot arise out of purely physical sources and our argument would be no different. Why abstractions cannot arise out of physical sources is not explained, and I think they clearly can. It’s easy to create an imaginary solution to an imaginary problem.

No, this is a clear case of missing the point. We know that at a fundamental level physical causes don’t act for reasons. The reason an asteroid hits the Earth isn’t because it thinks colliding with our planet is the best way to achieve some end. It is acting in accordance with the laws of physics, and these laws (plus relevant physical conditions) comprehensively explains the event. So we have a prima facie case against the physical constitution of rationality. Is an emergent account possible? Perhaps. Is such an account forthcoming? Doubtful. Therefore the argument constitutes a good reason to reject naturalism.

I take the following argument (word for word) from Steven Stich’s fantastic book The Fragmentation of Reason:

(1)Evolution is caused by natural selection.
(2)Natural selection will choose the best-designed (i.e., that most fitness-enhancing) system available in the gene pool.
(3)Over evolutionary time, a huge and varied set of options will be available for natural selection to choose among, and this set is very likely to include one or more that closely approximate a theoretical optimum.
(4)Systems produced by evolution can be expected to be about as well designed as it is possible to be.
(5)Our inferential system was produced by evolution.

For context, Stich is attempting to construct an evolutionary explanation of our belief that the human mind is rational (to whatever degree). He critiques every point, but what is most damaging to the case is that it is no way explains why the mind must be rational. There needs to be some ancillary proposition that states something like “Rationality has a monopoly on survival enhancing behavior.” I’m not positive that is a very helpful way to word it (I’m open to suggestions), but the missing premise needs to include something to the effect of survival-enhancing behavior necessitating rational beliefs. Since any missing premise built around that concept is probably wrong (and open to clear counterexample) there can be no evolutionary explanation of rationality (even if our minds evolved by the mechanisms of contemporary evolutionary theory).